public class Main {
    public static void main(String[] args) {
        MyStack myStack =new MyStack();
        myStack.push(12);
        myStack.push(23);
        myStack.push(34);
        myStack.push(45);
        System.out.println(myStack.pop());
        System.out.println(myStack.pop());
        System.out.println(myStack.pop());
        System.out.println(myStack.pop());
//        System.out.println(myStack.pop());
        System.out.println(myStack.peek());
    }
}